Submission #793591

#	Time	Username	Problem	Language	Result	Execution time	Memory
793591		Jarif_Rahman	Horses (IOI15_horses)	C++17	100 / 100	731 ms	60780 KiB

horses

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

const ll md = 1e9+7;
const ll L = 1e9+5;

struct segtree_for_product{
    int k = 1;
    vector<ll> P;
    segtree_for_product(int n){
        while(k < n) k<<=1;
        P.assign(2*k, 1);
    }
    void update(int i, ll x){
        i+=k;
        P[i] = x%md;
        i>>=1;
        while(i){
            P[i] = (P[i<<1]*P[(i<<1)+1])%md;
            i>>=1;
        }
    }
    ll product(int l, int r, int nd, int a, int b){
        if(a > r || b < l) return 1;
        if(a >= l && b <= r) return P[nd];
        int mid = (a+b)>>1;
        return (product(l, r, nd<<1, a, mid)*product(l, r, (nd<<1)+1, mid+1, b))%md;
    }
    ll product(int l, int r){
        return product(l, r, 1, 0, k-1);
    }
};

struct segtree_for_maximum{
    int k = 1;
    vector<ll> P;
    segtree_for_maximum(int n){
        while(k < n) k<<=1;
        P.assign(2*k, 0);
    }
    void update(int i, ll x){
        i+=k;
        P[i] = x;
        i>>=1;
        while(i){
            P[i] = max(P[i<<1], P[(i<<1)+1]);
            i>>=1;
        }
    }
    ll getmax(int l, int r, int nd, int a, int b){
        if(a > r || b < l) return 0;
        if(a >= l && b <= r) return P[nd];
        int mid = (a+b)>>1;
        return max(getmax(l, r, nd<<1, a, mid), getmax(l, r, (nd<<1)+1, mid+1, b));
    }
    ll getmax(int l, int r){
        return getmax(l, r, 1, 0, k-1);
    }
};

int n;
vector<int> X, Y;
segtree_for_product segx(0);
segtree_for_maximum segy(0);
set<int> candidates;

int query(){
    int fi = 0;
    ll p = 1;
    for(auto it = candidates.rbegin(); it != candidates.rend(); it++){
        p*=X[*it];
        if(p > L){
            fi = *it;
            break;
        }
    }

    ll ans = 0;
    p = 1;
    int j = fi;
    while(j < n){
        if(j != fi) p*=X[j];
        auto it = candidates.upper_bound(j);
        int nxt = n;
        if(it != candidates.end()) nxt = *it;
        ans = max(ans, p*segy.getmax(j, nxt-1));
        j = nxt;

    }
    ans%=md;
    ans*=segx.product(0, fi), ans%=md;
    return ans;
}

int init(int _n, int _X[], int _Y[]){
    swap(n, _n);
    X.resize(n), Y.resize(n);
    segx = segtree_for_product(n);
    segy = segtree_for_maximum(n);
    for(int i = 0; i < n; i++){
        X[i] = _X[i], Y[i] = _Y[i], segx.update(i, X[i]), segy.update(i, Y[i]);
        if(X[i] > 1) candidates.insert(i);
    }
    return query();
}

int updateX(int i, int x){
    if(X[i] > 1) candidates.erase(i);
    X[i] = x;
    if(X[i] > 1) candidates.insert(i);
    segx.update(i, x);
    return query();
}

int updateY(int i, int y){
    Y[i] = y;
    segy.update(i, y);
    return query();
}

Compilation message (stderr)

horses.cpp: In function 'int query()':
horses.cpp:97:12: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   97 |     return ans;
      |            ^~~

• Subtask 1: 17 / 17
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 23 / 23
• Subtask 5: 23 / 23